High-intensity focused ultrasound (HIFU) has been increasingly used in the field of molecular device applications to overcome problems of known technologies of treating samples. By means of the acoustic energy focused onto the sample sonophysical or sonochemical reactions can be caused in an efficient way. Furthermore in recent years, progress in many aspects of sample-in result-out devices, also known as micro total analysis systems or lab on a chip has been realized. For example the integration and miniaturization results in systems requiring a relative small, acceptable contamination risk of the sample, high sensitivity and short turnaround time of the test and lower costs per tests. Furthermore between sample input and result generation minimal operator intervention shall be required. Operator interventions can be done by relatively unskilled operators and moderate demands on operating environment.
Cavitation is defined as the phenomenon of formation of vapor bubbles of a liquid inner region when the pressure of the liquid falls below its vapor pressure. In molecular analyzing devices cavitation may be used to achieve lysis of cells within the sample that is to be treated with HIFU but also other treatment functions like mixing liquefaction may be caused by HIFU. Within known technologies the treatment functionalities mixing and lysing require different power levels, which may make it complicate to do both in one single chamber. To provide for high power systems large transducers are used and liquid cooling may be applied in order to avoid excessive heating.